November 03, 2014
Phase Out Fossil Fuels by 2100, IPCC Warns
by Robert Kropp

The Synthesis Report of the Intergovernmental Panel on Climate Change warns that further delay in
aggressive mitigation efforts will substantially increase the risks of severe and irreversible
impacts on human life and ecosystems.

One by one, for just over a year, the Working Group reports of the Fifth Assessment Report by the
Intergovernmental Panel on Climate Change (IPCC)
have been published, and their conclusions have been irrefutable. The atmospheric concentrations of
greenhouse gases (GHGs) are now at a level “unprecedented in at least the last 800,000 years,” the
first section of the report stated. “It is extremely likely that human influence has been the
dominant cause of the observed warming since the mid-20th century.”

The IPCC just
finished its Fifth Assessment reporting process with a synthesis report that brings together its
findings on the physical science of climate change, the impacts, and adaptation and mitigation.
“The Synthesis Report confirms that climate change is being registered around the world and warming
of the climate system is unequivocal. Since the 1950s many of the observed changes are
unprecedented over decades to millennia,” IPCC stated. “The report expresses with greater certainty
than in previous assessments the fact that emissions of greenhouse gases and other anthropogenic
drivers have been the dominant cause of observed warming since the mid-20th century.”

Going beyond the near-certainty of its scientific findings, the Synthesis Report is as
unequivocal in its assertion that global efforts to address climate change have been inadequate.
“Continued emission of greenhouse gases will cause further warming and long-lasting changes in all
components of the climate system, increasing the likelihood of severe, pervasive and irreversible
impacts for people and ecosystems,” the report states. “Limiting climate change would require
substantial and sustained reductions in greenhouse gas emissions which, together with adaptation,
can limit climate change risks.”

“Substantial cuts in greenhouse gas emissions over the
next few decades can substantially reduce risks of climate change by limiting warming in the second
half of the 21st century and beyond,” the report continues. And neither does the report equivocate
on what is meant by substantial cuts: “near zero emissions of CO2 and other long-lived GHGs by the
end of the century.” Any further delay in a global transition to a low-carbon economy, the report
warns, “will substantially increase the challenges associated with limiting warming over the 21st
century to below 2°C relative to pre-industrial levels.”

In any case, “Many aspects of
climate change and associated impacts will continue for centuries, even if anthropogenic emissions
of greenhouse gases are stopped.”

“It is technically feasible to transition to a
low-carbon economy,” said Youba Sokona, Co-Chair of IPCC Working Group III, who noted also that
mitigation of risk is manageable. “But what is lacking are appropriate policies and institutions.
The longer we wait to take action, the more it will cost to adapt and mitigate climate change.”

Government negotiators are scheduled to meet next year in Paris for another round of talks
on addressing climate change.